An LSD is nowhere near a locker in terms of what it can do for you offroad. For street use, an LSD is the right choice but for more difficult offroad trails, a locker is a more desirable choice. The first thing I did to my first TJ 16 years ago was to install front and rear LSDs. Within a few years of doing progressively more difficult offroad trails, I replaced them both with lockers which gave the Jeep a startling jump in offroad abilities... nearly as much as shifting from 2wd to 4x4.

Is this correct? Arent both wheels locked together?Is it because on a turn one wheel has to spin slower & being off the ground it THINKS your in a turn?

Only a locker locks the left and right wheels together.

A LSD only serves one purpose... to increase the amount of torque available to the tire with the best traction. Which can be misleading in a way since a LSD actually serves to equally increase the amount of torque sent to the axle which is then split 50:50 by the differential... whose net result is to provide more torque to the tire with traction which in many cases will be enough to help keep you moving.

It increases the amount of torque delivered to the tires by increasing how much torque the engine generates. How? By increasing the amount of resistance the engine works into. How? By using the LSD's clutch or gears to better couple the resistance seen by the tire with the better traction to the other side which has less or no traction. Which then presents more resistance to the engine which causes the engine to develop more torque which is sent to the axle. The more resistance an engine works into, the more torque it produces.